What the evidence says. Early or small human trials; promising but not yet conclusive.
Nutrition per serving 1 cup (135 g)
Water112 g83%
Sugars12.6 g9%
Other carbs8.4 g6%
Protein1 g1%
Fat0.3 g0%
What's in one serving, by weight — average composition (USDA).One serving as % of the adult daily requirement (FDA Daily Values). The bold outer ring = 100% of a day's needs.
Jambolan (Jamun / Java Plum) (Syzygium cumini) is a fruit used for traditional and preclinical antidiabetic / glucose-lowering activity (largely seed-based; best human rcts of leaf preparations were negative). NutriDex grades the human evidence as Preliminary. Jambolan is widely promoted as an antidiabetic fruit, but the human evidence is far weaker than its reputation. The best-controlled clinical trials used leaf tea/extract and were negative: a randomized, double-blind, double-dummy trial in 27 type 2 diabetics (Teixeira 2006) found S. cumini tea produced no change in fasting glucose, while glyburide lowered it significantly; an earlier randomized controlled trial by the same group (Teixeira 2004) reached the same conclusion. Most positive data come from seed (not pulp) powder studies and from rodent and in-vitro models, where anthocyanins and tannins show alpha-glucosidase/alpha-amylase inhibition, antioxidant, and lipid-lowering activity. A small open-label seed-powder trial (cited in Rizvi 2022) reported modest improvements in glycemia and dyslipidemia, but such studies are underpowered, short, and often co-administered with standard drugs. The fruit itself is a low-calorie source of vitamin C and potassium plus pigment polyphenols. Note that USDA SR Legacy does not report sugar or dietary fiber for this item, so its fiber content is unquantified in the reference database. Overall the weight of human evidence is preliminary and mixed, and rigorous, adequately powered RCTs of standardized preparations are still lacking.
Purported Benefits
✓Traditional and preclinical antidiabetic / glucose-lowering activity (largely seed-based; best human RCTs of leaf preparations were negative)
✓Antioxidant capacity from anthocyanins and polyphenols (mostly in-vitro)
✓Lipid-lowering / cardiometabolic signals in small human and animal studies
✓Anti-inflammatory activity in vitro and in rodent models
✓Astringent gastrointestinal use for diarrhea and digestive complaints (traditional)
✓Low-calorie source of vitamin C and potassium
Dosing & Compounds
Typical Dose
Culinary: ~100-135 g fresh fruit (1 cup). Studied antidiabetic preparations typically use seed powder (~5-10 g/day) rather than fresh pulp; benefits cannot be assumed from eating the fruit.
Active Compounds
Anthocyanins (delphinidin-, malvidin-, petunidin-, cyanidin-3,5-diglucosides)Hydrolyzable tannins / ellagitannins (gallic acid, ellagic acid)Flavonols (quercetin, rutin, myricetin)Phenolic acids (gallic, chlorogenic, ferulic acids)Seed alkaloid jambosine and glycoside jambolin (antimellin)Triterpenoids including oleanolic acidVitamin C (ascorbic acid)Minerals: potassium, magnesium, iron
Safety & Cautions
⚠
Generally safe as a food. Concentrated seed/extract preparations may have additive hypoglycemic effects with insulin or sulfonylureas, so diabetics combining them with medication should monitor blood glucose to avoid hypoglycemia. High tannin content is astringent and may reduce absorption of iron and some drugs; very large amounts may cause GI upset or constipation. Safety of medicinal doses in pregnancy and lactation is not established. The hard seed is a choking hazard and is not eaten whole. Educational only — always check with your doctor or pharmacist before combining Jambolan (Jamun / Java Plum) with any medicine.
Common questions about Jambolan (Jamun / Java Plum)
What is Jambolan (Jamun / Java Plum) used for?
Jambolan (Jamun / Java Plum) is most often taken for Traditional and preclinical antidiabetic / glucose-lowering activity (largely seed-based; best human RCTs of leaf preparations were negative), Antioxidant capacity from anthocyanins and polyphenols (mostly in-vitro), Lipid-lowering / cardiometabolic signals in small human and animal studies, Anti-inflammatory activity in vitro and in rodent models. Anthocyanin-rich tropical plum with antidiabetic folk use
Does Jambolan (Jamun / Java Plum) work — what does the evidence say?
Preliminary evidence. Early or small human trials; promising but not yet conclusive. Jambolan is widely promoted as an antidiabetic fruit, but the human evidence is far weaker than its reputation. The best-controlled clinical trials used leaf tea/extract and were negative: a randomized, double-blind, double-dummy trial in 27 type 2 diabetics (Teixeira 2006) found S. cumini tea produced no change in fasting glucose, while glyburide lowered it significantly; an earlier randomized controlled trial by the same group (Teixeira 2004) reached the same conclusion. Most positive data come from seed (not pulp) powder studies and from rodent and in-vitro models, where anthocyanins and tannins show alpha-glucosidase/alpha-amylase inhibition, antioxidant, and lipid-lowering activity. A small open-label seed-powder trial (cited in Rizvi 2022) reported modest improvements in glycemia and dyslipidemia, but such studies are underpowered, short, and often co-administered with standard drugs. The fruit itself is a low-calorie source of vitamin C and potassium plus pigment polyphenols. Note that USDA SR Legacy does not report sugar or dietary fiber for this item, so its fiber content is unquantified in the reference database. Overall the weight of human evidence is preliminary and mixed, and rigorous, adequately powered RCTs of standardized preparations are still lacking.
What is the typical dose of Jambolan (Jamun / Java Plum)?
Culinary: ~100-135 g fresh fruit (1 cup). Studied antidiabetic preparations typically use seed powder (~5-10 g/day) rather than fresh pulp; benefits cannot be assumed from eating the fruit.
Is Jambolan (Jamun / Java Plum) safe? Any cautions or side effects?
Generally safe as a food. Concentrated seed/extract preparations may have additive hypoglycemic effects with insulin or sulfonylureas, so diabetics combining them with medication should monitor blood glucose to avoid hypoglycemia. High tannin content is astringent and may reduce absorption of iron and some drugs; very large amounts may cause GI upset or constipation. Safety of medicinal doses in pregnancy and lactation is not established. The hard seed is a choking hazard and is not eaten whole.
How many studies support Jambolan (Jamun / Java Plum)?